Method and apparatus for setting self-moving bolster in presses

ABSTRACT

Self-moving bolster and the related devices used in press machines for pressing steel plates, operate to raise and lower automatically through wheels which are provided in the bolster itself. In order that said bolster can be set at a predetermined position smoothly and firmly in the press room, cooperating abutting members and positioning members are provided on said bolster and on the bed of the press, whereby the entry of said self-moving bolster into the press room of the press, positioning of the bolster therein or the removal of said self-moving bolster from the press room are all performed automatically.

United States Patent 11 1 Aisuta et a1. 7

1451 Oct. 15, 1974' METHOD AND APPARATUS FOR SETTING- SELF-MOVING BOLSTER IN PRESSES Assignee:

Filed:

Inventors: Hisayoshi Aisuta; Teiji Ueda;

Yokichi Koezuka; Hiroshi Asamoto, all of Komatsu, Japan Kabushiki Kaisha Komatsu Seisakusho, Tokyo-to, Japan June 12, 1972 Appl. No.: 262,106

US. Cl. 72/448, 100/1310. 18 1111. c1 B2lj 13/02 Field of Search 72/448, 427, 344, 345,

72/346; 100/229, DIG. 1 8

References Cited UNITED STATES PATENTS Myhrum Johansen Clements Danly Clements l2/l965 Clements 1. 100/43 3,306,185 2/1967 Soman 3,368,479 2/1968 Grcgorovich 3,422,662 l/l969 Gcuss 72/448 Primary Examiner-C. W. Lanham Assistant ExaminerGene P. Crosby Attorney, Agent, or Firm-Toren and McGeady [5 7 ABSTRACT therein or the removalof said self-moving bolster fromthe press room are all performed automatically.

- 4 Claims, 17 Drawing Figures sum w 5 FIG. 7 7 FIG. 8

ncnslsm 3.841.142 PATENTED 8am u N 5 4 |o| uoeil FIG. l5

PAIENIEMI 1 5mm SHEH SI)? 5 FIG. I?

FIG. l6

is quite troublesome.

l METHOD AND APPARATUS FOR SETTING SELF-MOVING BOLSTER IN PRESSES BACKGROUND OF THE INVENTION In a large-sized press machine used for pressing steel plates, it is conventional to use metal dies having a large volume and a heavy weight, so that it is generally difficult and dangerous to carry out the replacement or repair of the die in the press room. Accordingly, a transferrable bolster is used instead of setting said dies (generally consisting of an upper die and a lower die) on a bolster fixed on the bed of the press in the room, whereby said die is carried into and carried out of the press room after being mounted on the transferrable bolster. Thus, when the die is to be replaced, the die is carried out of the press room while it is still mounted on the transferrable bolster, and the replacement or repair of the die is carried out outside of the'pressroom.

Such a moving bolster is found to be very convenient especially for large-sized presses.

However, the movingbolsters which have been used have wheels, which are made to run on rails, and the bolster is made to stop by abutting a part of the bolster against a stopper provided on the bed in the press room, or by abutting the wheel against a stopper, after which the bolster is lowered by means of a lift mechanism located just below the wheels, and the bolster is set at a predetermined position by being clamped.

In such a case,-it is difficult to stop the bolster at a predetermined position due to a reaction etc. when the moving bolster is caused to abut against the stopper, and it is also difficult to position the bolster accurately when the bolster is lowered for the positioning, so that some correcting operation is required after lowering.

Another means for positioninga moving bolster in a press room involves a method in which a fitting hole in a press room, and also a columnar projection which is fittable in said fitting hole is provided at the lower surface of the moving bolster. Thus inv lowering the moving bolster, said projection is caused to fit into said fitting hole. Y

However, this is found inconvenient, because a considerable vibration is imparted to the moving bolster when it is positioned merely by means of a fitting hole having a circular section and'a columnarprojection which is fitted in said fitting hole.

Furthermore, since pressure pins to be inserted into a moving bolster are merely inserted loosely into inserting holes formed in the bolster, when the moving bolster is to be transferred, it is impossible to transfer the moving bolster, and-itbecomes necessary during each operation to pull out the-pressure pins; Furthermore, when the bolster is to.bejset; it. is necessary to put the pressure pins one by one at required positions, which With the present invention, it is possible to execute automatically all the operati'ons of self-moving bolsters by accomodating a motor for, moving the self-moving bolster, stopping it at a predetermined position, positioning it at a predetermined'position, and raising or lowering. the bolster itself, thereby obviating the position correcting operation.

. 40 having a circular section is provided at the bed portion SUMMARY OF THE INVENTION This invention relates to a method and apparatus for transporting a self-moving bolster used for a press for working steel plates press room, positioning and setting the bolster therein, and removing the bolster from' the press room.

The invention provides a self-moving bolster in'whic'h said bolster isadapted to lowered by retracting wheels, which are provided in'said bolster itself, when the selfmoving bolster, which can be transferred on rails by the wheels, is to be set at a predetermined position in the press room.

The invention further provides an abutting member and a positioning member on said bolster, and also an abutting member and a positioning member on the bed in the press room, whereby said bolster is stopped by abutting the abutting member of said bolster against the abutting member provided in the bed, then engaging or fitting the positioning member of the bolster with the positioning member provided on the bed by lower ing of said bolster itself, whereby the bolster is set automatically at a correct position in the press room.

The invention is so contrived that said bolster can be transferred with the pressure pins accommodated therein, and no hindrance to the operation is produced thereby.

Additionally, the invention provides a moving bolster and related-mechanisms adapted to put the pressure pins, accommodated therein, instantly to a working condition when said moving bolster retracts its wheels and is positioned and set surely and automatically at a predetermined position in the press room in a state without vibration, etc.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a front elevation showing a general view of the present invention, I

FIG. 2 is aside elevation showing a general view of the present invention,

FIG. 3 is a plan view of the essential parts at the left half of the carrier or the moving bolster according to the present invention,

FIG. 4 is a plan view of the essential parts showing the right half of said carrier,

FIG. 5 is a side elevation showing a raising and lowering mechanism at the left half portion of said moving bolster,

FIG. 6 is a side elevation showing the raising and lowering mechanism at the right half portion of said mov-' FIG, 9 is a plan view of the abutting member at the i bed side in no. 7,

FIG. 10 is a plan view showing a mechanism for generating a signal to stop said moving bolster, and. 'a mechanism for generating a signal for operating the raising and lowering mechanismto' lower the moving bolster,

FIG. 11 is a sectional view of a mechanism for posithe press room,

FIG. 16 is a sectional view showing the. relation between the moving bolster set in the press room and a die cushion mechanism provided in the bed, and

FIG. 17 is a detailed viewshowing the operatin mechanism of the pressure pins.

DETAILED DESCRIPTION OF PREFERRE EMBODIMENT The present invention will now be described referring to the accompanying drawings.

The press machine 1 for press working of steel plates comprises a crown 2, four uprights 3, 3, a bed 4, a slide 7 which slides up and down along guide members. 5, 5, provided on the uprights 3, 3, and which is mounted with upper die 6. at the lower portion, and a moving bolster 8 adapted to fix firmly on the bed 4.

The moving holster 8 comprises a bolster 9 and a carrier 10 on which said bolster 9 is fixed, and a lower die 12 is fixed at the upper surface of the bolster 9 after the moving bolster 8 is positioned in apress room 11 of the press'machine I. When it is necessary to carry out a pair of dies, made of an upper die 6 and alower die '12 for replacement, from the press room 11, the upper die 6 is mounted on the lower die 12 on the bolster 9, and the upper die 6 and the lower die 12 are carried out together from the press room 11 by the moving bolster 8. As shown in FIGS. 3 and 4, the carrier 10 is provided with wheels 13,13, 13a, 13a at four corners.

Thewheels l3, l3, of the carrier l'can be rolled with respect to rails l4, 14 provided on the bed 4 in the press room 11 and rails 15, 15 provided on thefloor at a height equal to that of said rails 14,.14. The carrier 10 is adapted to be lowered or raised through wheels l3, 13, 13a, 13a which are provided in the carrier 10 itself.

The running mechanism and the raising and lowering mechanism 16 of the carrier10 will be described referring to FIGS. 3, 4, and 6.

In FIG. 3, a running and driving motor 17 is mounted on the carrier 10, a gear 18 fixed on a Shaft of said motor 17 is engaged with a gear 23 fixed 'on a rotating shaft 22 extending in both lateral directions of the carrier and supported rotatably bybearings 19, 20, 21, and each of gears 24 fixed at both endsof a rotating shaft 22 which rotates integrally with the rotation of the gear 23 is engaged with a gear27 fixed respectively on r short shafts 26,26. 7

Next, both ends of an axle 29 supporting thewheels 13, '13,, 13a, 13a through bearings28, 28 are supported by a bifurcated supporting lever 30, and the bifurcated ends 31, 31 of said bifurcated supporting lever 30 are fitted andmounted rotatably to both ends of said short shaft 26, and each of the gears 32 fixed on the wheels l3, 13 is engaged with said gear 27.

Accordingly, when the motor 17 is operated, the rotating shaft 22 is rotated by the engagement of the gear 18 and the gear 23, and the wheels l3, l3, are rotated respectively by the engagement of the gear 24- and the for operating the raising and lowering mechanism, and

a gear 34 fixed on the shaft of this motor 33 is engaged with a gear 36 fixed on a rotating shaft 35 extending in both directions of the carrier 10.

The rotating shaft 35 is rotatably supported 'on a frame 41 of the carrier 10 by means of bearings 37, 38, 39, 40, and each of bevel gears 42, 43 are fixed at both ends of the rotating shaft 35. The bevel gears 42, 43 are engaged with corresponding bevel gears 44, 45, respectively, and the bevel gears44, 45 are fixed on the respective rotating shafts 46, 47 extending in a longitudinal direction of the carrier 10. The rotating shaft .46 rotates a threaded shaft 48 integrally through a coupling 48a, and further rotates a transmission shaft 50 through a coupling 49, the transmission shaft 50 being further so arranged that it rotates a threaded shaft 52 shown in FIG. 3 through a coupling 51. The rotating shaft 47 is also connected integrally with a threaded shaft 53 through a coupling (not shown), and further connected with a transmission shaft 55 through a coupling 54, and is so arranged that it rotates a threaded shaft 57 through a coupling 56.

The detail of the raising and lowering mechanism 16 by the rotationof said threaded shafts 52, 53, 57 will be described referring to FIGS. 5 and'6.

In FIG. 5, the threaded shaft 53 is rotatably supported at both its ends on a supporting member 58 having a channel-shape fixedon the frame 41 of the carrier 10 through bearings 59, 60. The threaded shaft-53 is engaged with an internally threaded transfer piece 61. On the shaft portions 62, 62 projecting on both sides of the transfer piece 61, there are pivoted the upper portions of the links 64,65 through bearings 63, and the links 64, 65 are pivoted by their lower ends on the base portion of the bifurcated supporting member 30 through a short shaft 66, respectively.

Accordingly, when the threaded shaft 53 is rotated, the transfer piece 61 moves along the threaded shaft 53 led by the externalthread of the threaded shaft 53, and the transfer piece 61 reciprocates forwardly and backwardly with the positive and negative rotation of the threaded shaft 53,

The wheels 13,13, 13a, 13a are mounted on the axle 29, both ends of which are fixed on the bifurcated supporting members '31, 31 throughthe bearings 32, 32.

Since the end portionsof the bifurcated member 31, 31 are pivoted on the shaft 26, the transfer piece 61 moves along the threaded shaft .53, and as the links 64, 65 change their positions from the inclined state (a) to the upright state ([3), the bifurcated supporting member 30 rotates in a counter-clockwise direction with the shaft are in;the vertical positionfB), the lowermost external periphery of the axle 13a supported by the bifurcated supporting member 30 exposes itself downwardly below the lowermost surface 67 of the supporting frame 41 of the carrier 10.

In the drawing, the numeral 68 designates a limit v switch operated by means of the-link 64, for detecting movement of the wheel 13a to'above the lowermost surface 67 of the carrier 10, and the numeral 69 designates a limit switch, operated by means of the link 64, for detecting movement of the wheel 13a to below the lowermost surface67 of the carrier, when the links 64, 65 assume vertical positions.

The raising and lowering mechanism 16 at the side of the threaded shaft 57 whichrotates integrally with the threaded shaft 53 through the coupling54, transmission shaft 55, and the coupling 56, is the same mechanism as, and is symmetricalto the raising and lowering mechanism 16 at the side of the threaded shaft 53 as showm in FIG. 6, and the same symbols refer to the same members. v I

A stopping mechanism 72 is provided which causes the moving bolster 8 to stop at a predetermined position when it is carried into the press room 11 by means of an abutting member70 provided on the lower surface of the carrier and an abutting member 71 provided on theupper surface of the bed 4 in the press room 11.

The stopping mechanism 72 willnow be explained referring to FIGS. 3, 7 and 9.

First, as shown in FIGS. 7 to 9, the abutting member 70 is fixed by means of fixing bolts 74, 74 at an engaging portion 73 provided 'at the lower surface of the placed below the lower surface of the frame 41 of the carrier 10. v In the drawings, the numeral 82 designates apositioning knock pin of the abutting member 70 at the side of the carrier 10, and the numeral 83 designates a posimember71 at the side 'of the carrier 10, andis provided, with its center conframe 41 of the carrier 10, and the abutting member 71 i is fixed by means of fixing bolts74a, 74a at an engaging portion 75 providedon the bed 4 in the press room 11. .The abutting member 70 has a plane, circular form as shown in FIG. 8, and is provided with a diametral, vertical abutting surface 76 at the lower surface thereof, the right half portion from the "vertical surface76 being made as a plane surface77 which is located upwardly from the lower surface of the frame 41 of the carrier. The left half portion from the vertical surface 76 is formed as a stepped portion 78 projecting downwardly from said plane surface 77. 7

Asshown in FIG. 9, said abutting member 71 presents a plane circular form which is smaller than said abutting member 70,'and is provided with a diametral,

vertical abutting surface 79' on the upper surface. On

the right half portion from this vertical surface 79 there is formed a stepped portion 81 projecting above the plane surface 80 of the left half portion, with the plane surface 80 being located inwardly from the upper surface of the bed4. 1 i

As shown in FIG. 7, said abutting members 70 and 71 are so formed that they contact closely when their abutting vertical surfaces 76, 79 are abutted against one another, and at the same time the lower surface of the stepped portion 78 of the abutting member 76 at the side of-the-carrier 10, that is, the side of-the moving bolster 8, is placed above the upper surface of the bed 4, and the upper surface of the stepped portion 81 of the abutting member 71 at the side of the bed 4 is formed with the longitudinal center line 84a. The abutting "member 71 at the side of the bed 4 is provided-at a position'on' the bed '4 corresp0nding to the abutting member at the side of the carrier 10. b

As shown in FIG. 10, a stop'directing mechanism 87 of the driving'motor 17 of the'moving bolster is comprised of a dog 85 and a limitlswitch 86 provided near the upright 3, and an operation directing mechanism for raising and lowering mechanism 16 of the carrier 10 is comprised of a dog 88 provided on the carrier 10 and a limit switch 89 provided near the upright 3.

In this case, said dogs 85, 88 are fixedon anattaching member 91 attached at the lower corner to the right end portion of the carrier 10 as shown in FIG. 4, and the limit switches 86, 89 are fixed on the attaching wall 92 provided-near the upright 3 at a predetermined position on the upper surface in'the press room 11 of the Furthermore, actuation of the limit switch 86 by the dog 85 to stop the driving motor 17 causes a signal to issue before a predetermined time at which the abutting member 70. at the carrier side abuts the corresponding abuttingmember 71 atthe bed side,'whereby the limit-switch 89 is operated by the dog 88, and the signal for driving the motor for operating the raising and lowering mechanism of the carrier 10 is so adapted that the signal is issued after a predetermined time since the abutting member 70 of the carrier 10 has been brought into abutment against the abutting membolt-inserting holes 99, 99, into the circular recess 97. A fitting member 104 is separately provided (refer to FIGS. 11, 12) comprising cross-shaped projections 101 extending radially from the center on the lower surface of a-flange portion 100, a stem portion 102 formed at the upper porti on,'and threaded holes. 103,,

103, in the flange portion 100. The fitting member 104 is fitted into thecircular recess 97, the stem porsurface of the carrier 10, thus forming a cross-shaped engaging projection 93, which is positioned above the longitudinal central line 84a to the left of the carrier 10 in the drawing. The cross-shaped engaging projection 94 is entirely the same as the cross-shaped engaging 7 projection 93, but .the cross-shaped engaging projection 94 is arranged below the longitudinal center line 84a to the right end, the position of the cross-shaped engaging projection 93, 94 being symmetrical with respect to .the transversal central line 84b and to the longitudinal direction 84a.

Referring now FIGS. 11 to 14, a bottomed circular hole 106 is formed on the upper surface of the bed 4, and threaded holes 107, 107, are formed on the bottom portion of the bottomed circular hole 106, with a knock pin 108 being set in position as shown.

A fitting member 112 formed with a cross-shaped groove 109 extending radially from the center on the upper surface is separately provided, formed peripherally with bolt attaching holes 110, 110, and formed with knockpin inserting hole 111 on the lower surface. The fitting member 112 is inserted into said bottomed circular hole 106, the bolts 1'13, 113, inserted into the bolt attaching holes 110, 110, are screwed into the threaded hole 107,107, and the knock pin 108 is inserted into the knock pin inserting hole 111 so that the fitting member 112 is firmly set in said bottomed circular hole-106, and the upper surface of the fitting member 112'is placed slightly below the upper surface of the bed 4. In this way, the cross-shaped positioning holes 95, 96 are-formed which correspond respectively with two cross-shaped engagingprojections 93, 94 provided on said carrier and which are respectively made detachable with the engaging projections 93, 94.

In this case, in order to facilitate the correction of the fitting member 104, the hole 98 and the stem portion 102; the bolt inserting hole 99 and the bolt 105; the circular recess 97 and the flange portion 100, are all fitted loosely, and the lower edges of the cross-shaped projections 93,94 and the upper edges of the cross-shaped positioning holes 95, 96 are each chamfered, and each of the respective guide surfaces l14a, l14bare particularly formed into'straight vertical wall surfaces so that the rectilinear portions bear the load uniformly and lighten the concentrated load disposed thereon. In this example, the form of the cross-shaped engaging projection is varied to-have a slight gap between one side of the cross and the other side at the cross portions.

In order that the pressure pins 115, 115,. to be inserted into the bolster19 mounted on the carrier 10 are not required to be removed at the transfer of the carrier 10, a construction is adapted $011181 the pressure pins 115, 1l5'are transferred without obstruction together with the carrier 10 Referring to FIGS. 15 to 17, a large number of the pressure pin inserting holes 116', 116, which pass in a checker-board'fashion through the upper to the'lower surfaces of 'the bolster 9, are communicated with a space 117 surrounded by the frame 41 of the carrier. On the upper portion of these pressure pin inserting holes 116, 116, they are each provided with an annular stepped portion 119 for preventing falling through of the pressure pins 115, 115, by'suspending the top portion 118 of thepressure pins 115, 115, to be'inserted into the inserting holes 116, 116 the distance from the upper surface of the bolster 9 to the annular step portion 119 being so set that the lowermost end of the pressure pin 115 inserted into the inserting hole 116 is located above a predetermined distance from the lower surface of the carrier 10, and at the same time that the upper end of the top portion 118 is located below the upper surface of the bolster 9.

In the drawing, the numeral 120 designates an inserting groove having a section of inverted-T shape for inserting a mounting bolt (not shown) for fixing the lower die 12 on the upper surface of the bolster 9.

Accordingly, the upper surface of a wear plate 123, which is arranged at the upper surface of a die cushion pad 122 fixed at the upper portion of a die cushion cylinder 121, is located below the upper surface of the bed 4 when the cylinder 121 is situated at the lowermost position, and at this time there is a predetermined space distance between the upper surface of the wear plate 123 and thelowermost end of the pressure pins 115, 115, inserted respectively into the pressure pin inserting holes 116, 116. The upper surface of the wear plate 123 abuts against-the lower end surface of the pressure pins 115, 115, due to the raising of the die cushion cylinder 121, which when raised further, exposes from the upper surface of the bolster 9, and causes to project therefrom a knock-out bar (not shown) provided on the lower die 12 mounted on the upper surface of the bolster 9 by means of the pressure pin 115.

' In FIG. 16, the numeral 124 designates a clamping mechanism for tightening the bolster 9 on the bed 4.

' The moving bolster and the related devices according to the present invention are constituted-as described above.

Firstly, there will be explained a situation in which the moving bolster 8 situated at a position shown by an imaginary line in FIG. 1 is to be set on the bed 4 in the press room 11 of the press 1.

The metal dies are replaced outside the press room 11 of the press 1, and the upper die 6 and the lower die 12 are mounted together on the bolster 9 of the carrier 10. Pushing a switch (notshown) to operate the driving motor 17 housed in the moving bolster 8, causes rotation of the wheels 13, 13, thereby causing movement of the moving bolster on the rails 15, 15, effecting its transfer onto the rails 14, 14. When the dog 85 fixed on the carrier 10 abuts the limit switch 86, the driving motor 17 is stopped, and the moving bolster 8 coasts thereafter and decreases rapidly in its speed. Then the abutting member 70 is provided-on the carrier 10 abuts against the corresponding abutting member 71 on the bed 4, and the moving bolster 8 is stopped. Next, when the dog 88'comes into contact with the limit switch 89, the operating signal to the raising and lowering mechanism'16 is issued. Until the operating signal is issued,

the wheels 13, 13, 13a, 13a of the carrier 10 expose their peripheral lowermost portions from the lower surface of the frame 41 of the carrier, and maintain .the rollable condition on the rails 14, 14. At this time, the links 64,165 shown in FIGS. 5 and 6 are "in a vertical state, and the links 64, are standing firm and upright 1 to'hold the wheels 13, 13, 13a, 13a in a rollable state between the short shaft -66 and the short shaft 26' through the shortshaft 66 and the bifurcated supporting member 30.

When an operating signal isvgiven to the raising and 9 1 slightly in the clockwise direction through the short shaft 66, with the short shaft 26 as the fulcrum. Thus the peripheral lowermost portions of each of the wheels 13, 13, 13a, 13a are transferred gradually inwardly from the lower surface of the frame 41 of .the carrier 10, thus resulting in the lowering of the frame 41 itself of thecarrier l0.

- In this manner, the carrier 10 is substantially stopped at a predetermined position in the press room 11 by the abutting member 70 preliminarily provided in the carrier 10 and by the abutting member 71 provided in the bed 4 before the commencement of the lowering of the I frame 41, but it.is not positioned accurately and completely.

Therefore, in order to the cross-shaped engaging projections 93, 94- on the lower surface of the carrier and the cross-shaped positioning holes 95, 96 set corresponding respectively to said cross-shaped engaging projections 93, 94 provided on the bed 4 are gradually engaged each with other,

whereby the position of the moving bolster 8 is corrected, Finally the links 64, 65 are inclined, and the lower surface of the carrier 10 comes into closecontact with the upper surface of the bed 4 so that the peripheral lowermost portions of the wheels 13,13, 13a 13a sink from the lower surface of the frame 41 of the carrier 10, and at the same time the engaging projections 93, 94 located. at the symmetrical position fit completely into re-adjusting holes 95, 96 respectively, whereby the carrier 10, that. is, the moving bolster 8 is positioned'on the bed 4 in the press room 11 automatically and accurately in forward and backward directions as well as to the right and left directions. In this way, when the lower surface of the frame 41 of the carrier IO-abutted perfectly on the upper surface of the bed 4, the limit switch 68 is operated by the inclination of the links 64, 65, causing the motor 33 to stop operating the raising, and lowering mechanism, and soon the moving bolster 8 is firmly fixed on bed 4 by a bolster clamping mechanism 124.

After mounting the upper die 6 on the slide7 and tinishing the positioning of the upper die 6 and the lower die 12, the press l-is operated, and by raising a die cushion pad 122 withthe operation of a die cushion cylinder 121, the pressure pins 115, 115, inserted in the inserting holes 116, 116, of the bolster 9 are raised from the wear plate 123, and the formed product is ejected after raising the slide 7 when the formation of the steel plate isoverdue to the lowering of the slide 7 through a knock-out bar (not shown) of the lower die 12.

Next, when it is desired to transfer the moving bolster 8 outside the press room 11 for the purpose of replace: ment of the metal Idies etc., is pushed a switch (not shown) to issue an order foroperation of the raising and lowering mechanism 16, the motor 33 operates to rotate the threaded shafts 48, ,52, 53, 57, the transfer piece 61 is transferred in a direction opposite tothe lowering of the carrier 10 so that the links 64, 65 will take a vertical position from the inclined position, and when the links 64, 65 assume thevertical state, each of the peripheral lowermost portion of the wheels 13, 13, 13a, 13a becomes exposed from the lower surface of the frame 41 of the carrier 10, andrelative thereto, the frame 41 of the carrier 10 israised. When the links-64, 65 take a vertical position, the limit switch 69 operates attain a correct positioning,"

and stops the motor 33, and the carrier10 is put in a movable or running state. e 7

Next, when a switch (not shown) is closed to operate the driving motor 17, and the wheels 13, 13, 13a, 13a

are rolled on the rails 14, 14, the moving bolster 8 is transferred outside the press room 11. Then when the end surface of the. moving bolster 8 abuts on a stopper (not shown) placed outside the press room 11, the moving bolster 8 is stopped, and there the replacement of dies can be carried out.

When the moving bolster 8 is transferred, the die cushion pad 122 of the die cushion device is placed below the bed 4', and the pressure pins 1 15, -1 l5, are held suspended from the bolster 9, with the lowermost end thereof located above the lower surface of the frame 41 of the carrier 10, so that the transfer is not hindered at all.

The abutting member 70 at the bolster side of the stopping mechanism of the moving mechanism and the 'by the cross-shaped engaging projection provided at the bolster sideand the cross-shaped position correcting hole provided at the bed side. Thusit is possible to place the moving bolster automatically on the bed and to set the position correctly bothin the directions right and left as well as forward and backward, that it is so efficient, and also it is possible to'maintain automatically the transferrable state through the wheels, and the moving bolster can be transferred conveniently without removing the pressure pins which are maintained in place. What is claimed is:

l. A method for setting a-self-moving bolster in a press comprising the steps of advancing said selfm'oving bolster on rails into a press room of saidpress;

stopping said bolster by abutting an abutting member provided on the lower surface of a, carrier for said bol-.

ster against an abutting member provided on the upper,

surface of a bed in said press room; said abutting member of said bolster being provided with a vertical abutting surface and also being provided with a center which conforms with a longitudinal center line of .said carrier; with said abutting member of said bed being providedwith avertical abutting surface engageable with said vertical abutting surfaceof the abutting member of said bolster; actuating a raising and lowering" mechanism provided for said bolster in order to lower said bolster by retracting wheels provided on said bolster; and engaging two positioning members, each havtudinal center line at the other end of said carrier, one of said positioning holes being arranged at a position to engage with one of said positioning members, and the other of said positioning holes being arranged at a position to engage with the other of said positioning members, whereby the bottom portion of said bolster is brought into close contact with the bed in said press room. r

2. Apparatus for setting a self-moving bolster by transporting said bolster into and out of a press room provided in a press including a bed, said apparatus comprising a driving mechanism for moving said bolster, wheels provided on said bolster, a carrier for said bolster, a raising and lowering mechanism for raising and lowering the wheels of said bolster, an abutting member located on said bolster and having a vertical abutting surface and also having a center which is conformed with a longitudinal center line of said carrier for said bolster, an abutting member provided on said bed having a vertical abutting surface engageable with said vertical abutting surface of said abutting member of said bolster, two positioning members, each having a cross-shaped engaging projection and being provided on the lower surface of said bolster, one of said positioning members being arranged on one side of the longitudinal center line and at one end of the carrier of said bolster and the other of said positioning members being arranged on the other side of the longitudinal center line and at the other end of said carrier, two positioning holes provided on the upper surface. of said bed in said press room, each having a cross-shaped groove, one of said positioning holes being arranged at a position to engage with one of said positioning members, and the other of said positioning holes being arranged ata position to engage with the other of said positioning members, said cross-shaped engaging projection being configured to fit closely within said crossing said raising and lowering mechanism, a threaded shaft connected to be rotated by said motor, a transfer piece engaging said threaded shaft, a pivoted link mechanism connected with said transfer piece to be pivotally actuated thereby, and a bifurcated supporting member pivotally mounted at one end thereof upon a fixed fulcrum on said bolster, said bifurcated supporting member rotatably supporting said wheels and being pivotally engaged with said linking mechanism at an opposite end thereof. 4. A moving bolster apparatus adaptable for moving a bolster to and from a press room provided in a press, including a bed, said apparatus comprising a bolster, a carrier for mounting said bolster, said bolster including pressure pin inserting holes, each having an annular stepped portion at the upper end thereof, pressure pins configured to be inserted into said inserting holes, said pressure pins having a height which is shorter than the height of said bolster, and an enlarged upper portion adaptable to engage said annular stepped portion of said inserting holes to enable said pressure pins to be suspended within said inserting holes, whereby when said bolster is transferred relative to said press room, said pressure pins are supported by said bolster itself in a manner whereby the lower ends of said pressure pins may be positioned above the surface of said bed in said ,press room, and whereby when said moving bolster is set in a predetermined position on said bed in said press room, said pressure pins are caused to project from the upper surface of said bolster by operation of a die cushion apparatus provided in said moving bolster apparatus. 

1. A method for setting a self-moving bolster in a press comprising the steps of advancing said self-moving bolster on rails into a press room of said press; stopping said bolster by abutting an abutting member provided on the lower surface of a carrier for said bolster against an abutting member provided on the upper surface of a bed in said press room; said abutting member of said bolster being provided with a vertical abutting surface and also being provided with a center which conforms with a longitudinal center line of said carrier; with said abutting member of said bed being provided with a vertical abutting surface engageable with said vertical abutting surface of the abutting member of said bolster; actuating a raising and lowering mechanism provided for said bolster in order to lower said bolster by retracting wheels provided on said bolster; and engaging two positioning members, each having a cross-shaped engaging projection and being provided on the lower surface of said bolster with two position holes, each having a cross-shaped groove and being provided on the upper surface of the bed in said press room, one of said positioning members being arranged on one side of the longitudinal center line at one end of said carrier, and the other of said positioning members being arranged on the other side of the longitudinal center line at the other end of said carrier, one of said positioning holes being arranged at a position to engage with one of said positioning members, and the other of said positioning holes being arranged at a position to engage with the other of said positioning members, whereby the bottom portion of said bolster is brought into close contact with the bed in said press room.
 2. Apparatus for setting a self-moving bolster by transporting said bolster into and out of a press room provided in a press including a bed, said apparatus comprising a driving mechanism for moving said bolster, wheels provided on said bolster, a carrier for said bolster, a raising and lowering mechanism for raising and lowering the wheels of said bolster, an abutting member located on said bolster and having a vertical abutting surface and also having a center which is conformed with a longitudinal center line of said carrier for said bolster, an abutting member provided on said bed having a vertical abuttinG surface engageable with said vertical abutting surface of said abutting member of said bolster, two positioning members, each having a cross-shaped engaging projection and being provided on the lower surface of said bolster, one of said positioning members being arranged on one side of the longitudinal center line and at one end of the carrier of said bolster and the other of said positioning members being arranged on the other side of the longitudinal center line and at the other end of said carrier, two positioning holes provided on the upper surface of said bed in said press room, each having a cross-shaped groove, one of said positioning holes being arranged at a position to engage with one of said positioning members, and the other of said positioning holes being arranged at a position to engage with the other of said positioning members, said cross-shaped engaging projection being configured to fit closely within said cross-shaped groove.
 3. Apparatus according to claim 2 wherein said raising and lowering mechanism for raising and lowering the wheels of said bolster comprises a motor for operating said raising and lowering mechanism, a threaded shaft connected to be rotated by said motor, a transfer piece engaging said threaded shaft, a pivoted link mechanism connected with said transfer piece to be pivotally actuated thereby, and a bifurcated supporting member pivotally mounted at one end thereof upon a fixed fulcrum on said bolster, said bifurcated supporting member rotatably supporting said wheels and being pivotally engaged with said linking mechanism at an opposite end thereof.
 4. A moving bolster apparatus adaptable for moving a bolster to and from a press room provided in a press, including a bed, said apparatus comprising a bolster, a carrier for mounting said bolster, said bolster including pressure pin inserting holes, each having an annular stepped portion at the upper end thereof, pressure pins configured to be inserted into said inserting holes, said pressure pins having a height which is shorter than the height of said bolster, and an enlarged upper portion adaptable to engage said annular stepped portion of said inserting holes to enable said pressure pins to be suspended within said inserting holes, whereby when said bolster is transferred relative to said press room, said pressure pins are supported by said bolster itself in a manner whereby the lower ends of said pressure pins may be positioned above the surface of said bed in said press room, and whereby when said moving bolster is set in a predetermined position on said bed in said press room, said pressure pins are caused to project from the upper surface of said bolster by operation of a die cushion apparatus provided in said moving bolster apparatus. 